THIS IS A TRAINING WHEEL SET MADE VERY STRONG,,BEST STRONG SETS I COULD FIND TO SELL IN OUR BIKE SHOP,,,,,THEY WILL FIT BIG 20 INCH BIKES BUT WILL ADJUST TO 16 IN AND 12 INCH BIKES,,,COMES IN A BOX WITH EASY INSTRUCTIONS,,SEE PHOTO THE WHEELS ARE MADE OF STRONG STEEL,,,NICE STRING STEEL BRACKETS,,NICE RUBBER TIRES,,I HAVE SOLD THE WHEELS ALONE FOR PEOPLE WHO NEED THEM FOR CARTS AND OTHER THINGS LIKE THAT. 242-808